1. Field of Invention
This invention relates to Photography, specifically to a mount for lights and rigging equipment.
2. Description of Prior Art
In the evolution of modern movie lighting equipment two types of mounts have become standard in the industry. The larger lights have a 1 1/8" pin (Junior pin) which slips into a 1 1/8" receiver in the stands and other supports that hold these lights. The smaller lights have a 5/8" receiver which slips over a 5/8" pin (Baby pin) on the stands and other supports for these lights.
Much of the rigging equipment used by the grip department of a film crew also uses the baby pin. An example is the C-stand, a much used piece of equipment which holds flags and serves as a universal support. This is a folding 3-legged stand with a telescoping center post which terminates in a baby pin. Atop this pin is a "grip head" which rotates on the baby pin and holds a 5/8" extension arm. This arm terminates in a "knucklell which is designed to grab another 5/8" pin. So, the baby pin and the receptacles that fit it are the basic and multi-functional connectors for mounting lights and grip equipment.
Many devices have been developed to provide baby pins for mounting lights and grip equipment. The majority of these devises were created by attaching a baby pin to an existing mechanism or clamp. Each has a limited application which necessitates carrying many different devises from film location to film location.
The prior art referred to below can be found in the catalogues of companies that sell motion picture equipment. Attached are copies of catalogue pages that show the specific prior art. The names and addresses of these companies are given below.
Prior art items A through R are from the catalog of Matthews Studio Equipment Inc., 2405 Empire Ave., Burbank, CA 91504.
Items (A) and (B) are the Century stand (C-stand) and the grip head and extension arm referred to earlier.
Item (C) Standard C-Clamp with one or more baby pins welded to it. These clamps are heavy and slow to open & close. They have little stability from side to side and tend to rotate around the small circular jaw faces. Some have special jaws for clamping pipe, but even those don't hold well on cylindrical objects. The jaws of these clamps tend to mar the surface they are clamped to and their size and shape make it difficult to get them into tight spots. Over time and after use in wet weather, the threaded shafts of these clamps rust and make it difficult to operate the clamps.
Item (D) Furniture Clamp with 5/8" pin. These clamps are long and useful if clamping something 6" or more thick. They will not clamp to cylindrical objects. They mar the surfaces they are clamped to and these clamps also tend to rotate around their small jaw faces.
Item (E) Chain Vise Grip. These devises clamp by tightening a length of chain around an object. These clamps tend to scratch or dent objects they are clamped around. They can only clamp to objects that can be encircled with the chain and they are not stable from side to side perpendicular to the circle of chain.
Item (F) Vise Grip. These clamps will securely grab flat objects (those with parallel planer faces) up to 111 thick. When opened wider than 111 the jaws do not hold securely because they do not remain parallel as they open. When opened over 111 the jaws are further apart at the end away from the pivot point than they are at the end near the pivot point. This makes the clamp slip off the object it is clamped to. When trying to clamp cylindrical objects over 1 1/2" diameter, the non-parallel jaws will again cause slippage.
The strong clamping force of these clamps, and the small contact area and teeth of the jaws will mark the wood or metal that they are clamped to.
Item (G) Baby Grid Clamp. These clamps form a good attachment on cylindrical objects. They are limited though to diameters between 11/4" to 11/2". The jaws are not padded and they require a wrench to attach and detach them.
Item (H) Baby Pipe Clamp. These clamps form a secure attachment for hanging a light on 11/2" to 21/2 "pipe. They do not attach well on smaller diameters. The lock bolt always leaves a mark and they require a wrench to attach or detach. Because the jaw is no more than 11/4" wide, they are not stable enough side to side to use for mounting most rigging equipment.
Item (I) McMatth Clamp. This clamp is well designed and forms a strong attachment to various sizes and shapes. It does have padded jaws. Its size and weight (8 pounds), however, make it unacceptable for almost all applications on location and most applications in the studio.
Items (J) and (K) The Gaffer Grip and Grip-A-Light. Both of these are spring loaded clamps and will support only small lighting instruments. The jaws do not remain parallel so contact area on flat surfaces is usually small. As a mount for grip equipment they are severely limited.
Item (L) Baby Plate. This is a plate with a perpendicular baby pin. It is usually attached with screws. It's often used to mount a light on the top of a set wall. It takes time and tools to attach or detach and it leaves screw holes when removed.
Item (M) Drop Ceiling Scissor Clamp. Used to hang lights from conventional T-bar drop ceiling frames only.
Item (N) Heavy Duty Flag Clamp. These grab cylindrical shapes only, have no padding and weigh 3 pounds. They will mar a surface they are clamped on.
(0) Baby Matth Pipe Adapter. This is a light duty clamp which grabs cylindrical shapes only. Very limited applications.
(P) Crowder Hanger. Made specifically to mount on 2.times.4 or 2.times.6 lumber. (Q) and (R) Mafer Clamp and Foto Clamp. See end of Prior Art text.
Prior art items (S) and (T) are in the catalog from American Studio Equipment, 8922 Norris Ave., Sun Valley, CA 91352
(S) Magazine Clamp. This is an adaptation of a set of jaws from a hobby vise called a Pan-A-Vise. It comprises two flat parallel jaws with a nominal capacity of 0" to 6" and a baby pin. This clamp is attached to the film magazine of a camera in order to brace the camera for a moving shot. This is often accomplished by attaching one end of a C-stand grip head and extension arm to the magazine clamp and the other end to an adjacent secured baby pin clamp of some sort. This is not a heavy duty clamp. Its jaws are not designed to grab cylindrical objects. This clamp is usually used only for the aforementioned purpose.
(T) 2.times.4 slider--this is designed strictly for attaching a baby pin to a length of 2.times.4 lumber.
Prior Art (U) through (X) are in the catalog from Norms Studio Equipment, 5219 Craner Ave., North Hollywood, CA 91601.
(U) Bead Board Holder. This is a baby pin welded to a vise grip which has been fitted with large (approximately 6" by 6" by 1/16") flexible jaws. These jaws are designed for holding 4' by 8' sheets of foam core or styrene bead board. The clamp is held in place by grabbing the baby pin with a C-stand arm or some other means of support. This clamp can be used to support other objects but the jaws limit such use. The jaws are quite flexible and they do not stay parallel when opened so they are not secure enough to hold more than a few pounds. This clamp could be used for mounting small lights in some circumstances, but it is not a common practice.
(V) Super Clamp. See end of Prior Art text.
(W) Clamp with 5/8" male. This is a light weight spring clamp with a baby pin. The limited holding power of this spring clamp limits the use to very lightweight rigging equipment (maximum 2 lbs.).
The following clamps have been grouped together and left for last because they most closely relate to the object of this application.
(Q) Mafer Clamp, (R) Foto Clamp, and (V) Super Clamp. These are clamps specifically built to use for Photography. The Foto clamp is a less rugged, less expensive version of the Mafer Clamp. The Super clamp is yet another version of the same clamp.
The Mafer clamp was intended to be light-weight and versatile. It was intended to be used for mounting lights and rigging equipment and for supporting various objects on the set. This clamp is indeed light-weight but the design of the jaws has limited its versatility. The design of the hinged jaw is such that the jaw travels 3 times the distance that the threaded shaft of the tightening knob travels. This reduces the amount of leverage on the jaw. It is often difficult to get this clamp tight enough to hold firmly.
The pad on the fixed v-shaped jaw is plastic and in spite of a cross-hatched pattern does not grip well. So, this clamp slips on smooth round surfaces. The smaller the diameter of the object being clamped, the greater the tendency to slip. This is partially because the hinged jaw presses 1" diameter and smaller objects against one side of the V-notch rather than into the center of the V where the V shape has a pinching effect. On cylindrical objects this clamp is only affective an 11/4" to 2" diameters and does not work well on smooth surfaces.
When clamping flat objects the jaws are ineffective over a thickness of 11/4". Thus, this clamp will not grab 11/2" thick lumber. It is common in the film business to need to clamp to 2.times.4, 2.times.6, or 2.times.12 lumber. A different clamp is needed to do this.
This clamp does not work well on thin or flexible sheet material either because the jaws are not in direct opposition when they contact the material being clamped. The hinged jaw contacts the material between the two edges of the V-grooved jaw. Thus, thin or flexible materials bend or break when clamped.
Lateral stability can also be a problem with this clamp. This is partially because the jaws are only 13/4" wide, but more of the problem is again in the design of the jaws. When clamping cylindrical objects, such as a 1" outside diameter pipe, the face of the hinged jaw is nearly parallel to the inside face of the V-notch. The pipe is not forced into the V-notch where its lateral movement would be limited. Instead, due to the give in the 3/16" thick rubber pad on the upper jaw, the pipe can move sideways between the nearly parallel jaws.
When it comes to supporting objects on the set, this clamp is again limited by its jaw design. There seem to be few shapes that can be securely held in this clamp.
As yet there is no clamping mount that is indeed light-weight and will securely clamp a wide range of objects of various shapes and dimensions.